


Coiled in Your Embrace

by TwilaFrost



Category: Haikyuu!!
Genre: Alpha Sakusa Kiyoomi, Alternate Universe - Fantasy, Anal Sex, Breeding, Claiming Bites, Japanese Mythology & Folklore, Kitsune Miya Atsumu, M/M, Mating Bond, Mating Cycles/In Heat, Mpreg, Multiple Orgasms, Naga Sakusa Kiyoomi, Non-Traditional Alpha/Beta/Omega Dynamics, Omega Miya Atsumu, Rimming, Size Difference, Snake Anatomy, Suna Rintarou Deserves Better
Language: English
Status: Completed
Published: 2021-02-03
Updated: 2021-02-03
Packaged: 2021-03-14 10:40:16
Rating: Explicit
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 7,335
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/29169735
Author URL: https://archiveofourown.org/users/TwilaFrost/pseuds/TwilaFrost
Summary: Atsumu doesn't want a mate, at least, not yet. First, he wants to gain all nine of his tails. To do that, he needs to become more powerful. He's never seen a naga before. They're old semi-divine beings in this world and have enormous amounts of knowledge and power. When word reaches Atsumu that there's a naga possibly living at Lake Itachi, he leaps at the change to find out.
Relationships: Miya Atsumu/Sakusa Kiyoomi
Comments: 34
Kudos: 403





	Coiled in Your Embrace

**Author's Note:**

> This was originally a thread fic. It somehow became enormously long, so I decided to post it here. Umm, yeah, so if you like A/B/O and mythical beings then you've come to the right place. I hope that you like this and don't perceive me too hard. 🙈

In the five centuries that Atsumu has lived, he's heard the stories, and he's seen the statues - strange statues depicting serpentine humanoids with several heads. It's said that the males are strong and handsome while the females are striking beauties. However, Atsumu finds nothing appealing about a snake with seven heads. 

Not that he's actually ever seen a naga before, but they can't be all that. For beings that were supposedly overpopulating the Earth and now live in an underground kingdom, they sure are elusive. Atsumu sees more kitsunes, who are actually dwindling in numbers, than he's even heard of a naga sighting. Or maybe he has seen one and just didn't know it because they were in full serpent or human form. Semi-divine beings are tricky like that. Kitsunes have three forms too, after all. 

After 500 years, there's not much Atsumu hasn't seen. Aran always says that he's too nosey for his own good, but Atsumu isn't  _ nosey _ , he's  _ curious _ . Osamu is the nosey one. It's a bad habit he's picked up from Suna, though his twin isn't as subtle about it as he thinks he is. 

So maybe Atsumu wants to see a naga to see what all the fuss is about. Their kingdom Naga-loka is supposed to be magnificent with its resplendent palaces that are beautifully ornamented with precious gems. Too bad no one except naga know how to get there. Unless you're  _ really _ good at adventuring or somehow stumble upon by accident. But there are other places nagas hang around. Like water. 

Word has traveled that a rather unpleasant individual has taken up residence in Lake Itachi. It could be nothing, it could be something, or it could be a naga. Atsumu isn't going to hold his breath, but he's still going to go check it out. So he shifts into his five-tailed fox form and heads towards his destination. If it really is a naga, then something must have drawn it there. They're guardians of treasure, after all. 

Unlike some believe, nagas aren't inherently evil. In fact, they are typically benevolent beings. However, this creature sounds to have woken up on the wrong side of the bed for the last century if gossip is anything to go by. He heard it from his tengu friend, Atsumu will just have to find out for himself. 

He's well on his way when he wonders if he remembered to leave a scroll for Osamu…

  
  


Atsumu loves the stretch of his legs when he runs through the forest. He hasn't run like this in a while, and he’s reminded again why he loves it. Even with his swift movement, Lake Itachi is a good two day's journey. It gives him some time to reflect. 

The elders at the shrine tell him that he should have settled down with a mate by now. Most kitsunes do by their third tail. His unmated status is definitely not from a lack of suitors. They're crawling out of the woodwork to try and court him. Even beings of other species have come to the Inari Shrine to ask for his hand. And why is it that Atsumu has to beat all these suitors back with a stick? There are a few reasons. 

One, Atsumu is a male omega kitsune. "A treasure" if what one of the elders told him is anything to go by. So what if his loins are the holy grail of fertility? He's not about to sit at home and pop out kits. And that transitions into number two. 

Atsumu has five tails. He's more powerful than the average omega because he didn't stop collecting knowledge and power to build a family. Apparently, that's "hot." 

And then there's number three. Atsumu is attractive. Very attractive if he says so himself. All kitsunes are beautiful in their own rights. However, Atsumu just happened to win the gene pool lottery. It's not his fault nature decided to bless with good looks. Plus, Osamu has the same face. Except he's an alpha. And that's the thing, Osamu isn't mated either and no one's busting his balls about it! 

Double standards. 

And look, Atsumu knows it's because their species is dwindling, but Atsumu wants to live, okay? When he has all nine tails he'll finally settle down. The elders at the shrine disapprove of this, but that's just too damn bad. He'll appease them when he pleases. He'll most likely end up choosing one of the front runners anyway if they're still available.

That's the only part he feels a little guilty about. Both Kita and Suna have been vying for his affections for years, and he considers both of them close friends. He's not trying to lead them on or anything. They both know how he feels about the situation. Though he heard Kita has found interest in a female kitsune at another shrine. Atsumu is happy for him, he deserves someone who cherishes him.

However, Suna seems dead set on having him as his mate. Atsumu knows he's Osamu's choice. And honestly, it makes him a little giddy at the thought of being Suna’s mate. He’s even making an effort to keep pace with Atsumu in gaining his tails. Bastard already has five as well. Atsumu is only slightly impressed, though he’ll never admit it out loud. 

  
  
  


Towards the end of his second day of traveling, Atsumu catches a whiff of lake water. It's very distinctive. When he breaks through the treeline, he sees it. Slowing his pace, he shifts back into his humanoid form. It's magnificent. Atsumu doesn't think he's actually ever been here before. 

The mountains in the background make the scene before him worthy of one of those folktales. Not seeing any creatures in sight, he decides to rest for a moment before scouting out the area. There's definitely  _ something _ here. He can sense it. What it is, he's not sure yet, but he's determined to find out. 

When it's said that nagas are guardians of treasure, that doesn't just apply to material riches. It also applies to spiritual wealth. And well, there's a lot of ways that can be interpreted. Atsumu has a lot of searching around to do, but for now, he could go for a small nap.

  
  
  


He's rudely awoken by a lack of oxygen. Atstumu's eyes snap open to the sight of something thick, muscular, and scaley wrapped around him. Following the length, he makes eye contact with a human torso with olive green hair and eyes attached to a massive serpentine body. A naga.

He peers down at Atsumu through his slitted eyes. "Well, well, look what we have here. A kitsune? How peculiar."

The more Atsumu struggles, the tighter he's squeezed. He can't even rub his tails together to make fox-fire from this position.

"Let me go, ya Snake Bastard!"

"Why? So you can run away? That's no fun," he says, sticking his tongue out like, well... a snake.

Somehow Atsumu doesn't quite think this is the creature that he's heard about inhabiting the lake. He's more irritating than cranky. Regardless, Atsumu wants free.

"Fuck you. I didn't even do anythin'."

The naga lies beside where Atsumu is still coiled tightly and crosses his arms behind his head. "Well, you're awfully far away from one of your little shrines. Looking for something perhaps? Or someone?" The grin he gives Atsumu sends chills up his spine.

"Nope, just passin' through. Needed a little rest. I'm good now so I can just mosey on my way." Atsumu will gladly mosey on his way. Or at least get free so he can blast this bastard with his fox-fire.

"Oh?" the naga sticks his tongue out again. "Smells like you’re close to your heat. Are you sure you aren't looking for a mate?"

Atsumu balks. What? He shouldn't be- He wouldn't have left if that was the case. The naga's lying. He has to be. Or is he forgetting about something?

"You look surprised, little kitsune. Tell me, what does your Kami represent?" Well, rice obviously. Then overall agriculture. Then Inari was a protector of sorts. She represents prosperity and now industry as well. "What do human women pray to your Kami for?" the naga prompts.

"They ask her to grant them children," he says.

"Very good." What a patronizing asshole. "And I suppose you don't know what we naga are deities of?"

"Yer guardians."

"Yes, but we're  _ deities _ of water and fertility."

Atsumu doesn't like what he's insinuating here. He's not sure how it affects his heat, but something is happening. Inari's fertility is meant to represent plentiful soil, not  _ birth. _ Humans just don't know the difference apparently. Or... he supposes it can be interpreted in that way as well…

"Alright, but what does that have to do with anythin'?" he asks.

The naga's smile is downright malicious. "We're compatible beings! The longer I have you wrapped up like this, the more my pheromones entice your heat to cycle to speed up its course."

Atsumu's eyes bulge. "What the fuck!" He struggles to get free again, growling at the naga. 

However, both he and the naga freeze when they hear the surface of the water break. It sounds like something massive just emerged. Atsumu turns his head towards the lake to witness a spectacular sight. It's another naga. And he's- oh.  _ Oh. _ Okay, so maybe the tales were right because he's not just handsome and strong, he's fucking  _ hot. _

Water trickles down his sculpted body. It's like he's sculpted from the same marble as those damn statues.  _ Fuck. _ His wet, black hair sticks to his head, though he runs his fingers through it, fluffing it out. And damn, Atsumu is losing it. Deep emerald green eyes assess the two of them as the rest of his obsidian tail emerges from the water. He's huge. Just his human torso must be around 200 cm, and that's only a third of his entire length. Atsumu swallows thickly. Oh, fuck.

"Daishou," the new naga says, "what the  _ fuck _ are you doing?"

His  _ voice. _ A full-body shudder rips through Atsumu. It's so powerful and deep. An alpha. Oh, fuck indeed. 

The naga named Daishou laughs nervously. "Sakusa! I'm just talking to this kitsune here."

The naga - Sakusa - raises an eyebrow. "Did Mika throw you out again?"

"No!" Daishou sputters.

"Then why the fuck are you here?"

They continue their conversation as if Atsumu isn't even there. And well, Atsumu is okay with that because it gives him more time to feast his eyes on this absolute unit of a man. He's not sure how long he's been in his head when he's brought back to reality.

"Are you going to answer me or not?" Sakusa asks.

"Uh, sorry. Couldja repeat that?"

He sighs heavily. "I asked who you are and why you're in my territory."

"I'm Miya Atsumu, and I came to see who was causin' the ruckus up here."

"Well, now you've seen, and now you can go. Daishou, release him."

It's a relief when he sucks in a full breath of air. Then he turns his narrowed eyes to the Snake Bastard. "Thanks for the rib bruisin' asshole." 

Atsumu stalks forward, rubbing his tails together to create his fox-fire. Heh. Good thing it's so difficult for snakes to slither backward. He sends a bolt towards Daishou, nothing  _ dangerous, _ but it's sure to hurt.

"Ow! Fuck! I wasn’t actually going to do anything! I was just messing around!"

Atsumu doesn’t care, he’s pissed. He sends another in Daishou’s direction. Sakusa just watches as Atsumu continues to pelt him with fiery blasts, chasing him away and back to wherever he came from. Good riddance. Atsumu huffs. Damn snake. 

Turning around, he jumps, having forgotten that Sakusa was there. He's watching Atsumu with his arms crossed and dark eyes.

"Perhaps you're more interesting than I thought."

Atsumu can only watch as this massive god of a man slithers towards him. Sakusa looms over him - Atsumu's head only reaches his navel. He holds stock still as the naga bends down and fucking  _ licks _ him, making Atsumu's eyes widen.

"Hmm." The low rumble from Sakusa surges through Atsumu's body. What the hell is that supposed to mean? "What are you really doing here, Miya Atsumu?"

The compulsion to tell this creature everything washes over him. He's not  _ scared, _ exactly; Sakusa hasn't shown any sort of hostility towards him. But something deeply rooted inside himself screams  _ submit. _ Atsumu cranes his neck up to look Sakusa in the eye, defying that inner voice. 

"I wanted to know if it was a naga livin’ here."

"Why?"

"I was curious about them."

"And is your curiosity satisfied?" Sakusa begins to circle him, his long body surrounding him in a large space.

_ No. Not at all _ . He wants to say. But where would that lead him? Does he dare find out? They say curiosity killed the cat, but well, Atsumu isn't a cat.

"I haveta say, I'm even more curious now."

Sakusa's face lowers to his level."Then perhaps I can show you."

"By all means, show me what's brought ya here."

Sakusa smirks at him and jerks his head, indicating for Atsumu to follow him. For such a large creature, he sure moves fast. Atsumu is half tempted to climb on his back. Would he even notice? He decides better of it and jogs to keep pace with Sakusa's human torso.

"So, yer name's Sakusa? Got a first name to go with that?"

Sakusa glances down at him, not bothering to slow down. "Sakusa Kiyoomi."

"No fancy title or nothin'?"

"Well, you can always call me Sakusa-dono." He smirks at Atsumu's displeased expression.

"The best yer gonna get from me is Omi-dono." 

Atsumu revels when it's Sakusa's turn to be perturbed. "I'd rather you not." 

"Omi-dono it is!" Sakusa groans. Though apparently, he isn't bothered enough to not still lead Atsumu to wherever it is they're going. 

  
  


Lake Itachi sits in a glade near Nohebiyama's basin, but the further they go, the more Atsumu feels that something amazing is about to be discovered. A small river flows from the lake and leads towards a cave. And to be frankly honest, Atsumu didn't know there was even a river here. Or a cave. But the closer they get, the more he picks up on a few peculiar scents. Salt and... what is that? Sakusa stops at the entrance. 

"Go ahead first."

Atsumu glances at him, slightly weary, but pushes onward. Taking a step in, he's in awe. It's... glowing. A light blue lights up the cave's ceiling. He steps alongside the river that flows so gently, it seems to not be moving at all. Sakusa himself slither's along inside the river with his torso still well above the surface as his massive size would be a bit cramped on the land.

"What is it?" Atsumu asks. He doesn't sense any type of magic at play here.

"They’re glowworms."

"Wow. I can see why ya like it so much." It’s truly an enchanting sight.

"This isn't even the best part," Sakusa says. "We should be getting there at the perfect time." There's more? Atsumu's eyes sparkle, wondering what lays ahead. 

The cave lets out into an alcove that opens up into a beach. And oh… It's twilight. Stars shine through the purpling sky, and the water glows blue - just like inside the cave.

"Plankton," Sakusa says. 

Atsumu walks towards the tide, letting the luminescent water flow over his bare feet. There's a lot he's seen in the last 5oo years, but this isn't one of them. Nor is a cave lit up with glowworms or meeting a naga. Two nagas, in fact. 

Sakusa slithers close enough to touch. His tail brushes Atsumu's legs. "Tell me, Miya Atsumu, what do you think? Are you pleased?" 

He turns, a little surprised to see that Sakusa is  _ right _ there, his human torso level with Atsumu's own body. 

"I am." 

Sakusa's eyes gleam. "Good." 

He reaches out with his large hand and caresses his cheek. Atsumu's breath hitches and his heart stutters in his chest. Is... is this- Is he being  _ courted _ right now? How do nagas even court? And  _ why  _ is a naga trying to court him? Or is he just thinking crazy right now? Well, there's one way to find out.

"Omi-dono, are ya tryin' to court me right now?"

"No.” He leans closer. “I  _ am  _ courting you right now." 

Atsumu's heart hammers against his chest walls.  _ Oh. _ He swallows thickly. Well, there's his answer. “Why?"

"There's something about you that I can just sense. It's not completely unheard of. Others of my kind have described a similar feeling before."

"And what does it mean?"

"In my language, you're my belahan jiwa, which essentially means a section of my soul." Is he saying that Atsumu is his  _ soulmate?!  _ "But I don't necessarily believe in that. I do, however, trust my instincts."

Atsumu is vaguely aware of the coils of dark scales drawing closer to him. "And what do yer instincts say?"

Sakusa's other hand settles on his waist. "That I want you, Miya Atsumu. I want you to be my mate."

Atsumu feels so  _ small  _ right now but strangely content. Despite being cold-blooded, Sakusa's hands are warm where they hold his face and body. He can feel Sakusa's breath on his lips, almost touching.

"Atsumu!"

His attention snaps to the familiar voice, eyes widening at the sight.

"Sunarin?!"

Sakusa immediately pulls Atsumu to him, going into defense mode and hissing at the intruder. Suna's tails bristle at the sight. 

"Let Atsumu go, naga!"

"Says the kitsune who is trespassing on my territory."

This is bad. Really bad. What is Suna even doing here? Did he follow Atsumu all the way from the shrine?

"Omi-dono, it's okay. Lemme talk to him."

He's reluctantly released and makes his way over to Suna, who is in a staring contest with Sakusa. Though he's pulled into a tight embrace by his fellow kitsune. Sakusa's sharp hisses ring in his ears as Suna rubs his scent all over him. 

"Sunarin, what're ya doin' here?"

"Osamu went absolutely ballistic when you just disappeared. It's almost the lunar solstice!" Oh. He totally forgot about that. "So we tracked you. And it's a good thing too. Who knows what would've happened if I had been just a moment later. Now, let's go." 

He keeps an arm around Atsumu's waist and begins walking. Atsumu is a bit dumbfounded and unconsciously walks forward. They don't get far before the ground gives a slight rumble. Sakusa is slithering after them with a heated look in his eyes. 

"Where the  _ fuck _ are you taking my mate?!"

Suna's eyes flash dangerously. " _ Your _ mate?! He's going to by  _ my _ mate once we both have all nine tails! Right, Atsumu?"

Atsumu's eyes widen as he looks between the two alpha males. Fuck.

"Well, technically, I never agreed to anythin' to either of ya." He crosses his arms.

"Great! Let's go home then," Suna says, latching onto Atsumu again.

A sound between a growl and an honest to god roar rips from Sakusa. An alpha's challenge if he's ever heard one. That's Atsumu's cue to duck out. Because fuck, that's scary. And strangely arousing. 

Atsumu runs off to the side when Suna lets go to take a fighting stance. Atsumu has a bad feeling about this, but he can't intervene. He's not supposed to at least. It's meant to be a one-on-one duel of sorts. Especially when it's in regard to a potential mate. He knows Suna is a good fighter, but Sakusa is just... so much bigger than him. If he gets close then…

Suna makes the first move, rubbing his tails together to form his fox-fire and sending a blast right at Sakusa. There's not much he can do to avoid being hit. But he presses on, even as Suna kites him with ranged attacks. 

Sakusa's speed is lightning quick. He springs forward, biting Suna on the shoulder before recoiling back. Suna stumbles and falls to the ground. He staggers, trying to get back to his feet, but Sakusa is already on him. His tail wraps around his body. Okay, Atsumu has seen enough, there's a clear winner here.

"Stop!" He runs to where Suna is tightly bound. "Let him go, Omi!" 

The anger in Sakusa's eyes mixes with hurt but does as requested. Atsumu kneels down and cradles Suna's slumped head. "Oh my god." 

About that time is when Osamu comes running out of the cave alcove. "'Tsumu! Rin!" 

He freezes in place, seeing Sakusa's looming figure over his brother and friend. Osamu approaches tentatively when Atsumu waves him over.

"Omi-dono, what kinda venom is this?" he asks.

"I only used paralysis. He'll be fine in a few hours."

"Oh thank god." Atsumu slumps back.

“Tsumu, what's goin' on? What happened?” Osamu searches his face, his tails twitching behind him.

"Omi-dono and Sunarin... they-" he goes on to explain. Sakusa stays put, seemingly keeping watch of the whole scene, though he does answer Osamu's questions when prompted.

"So yer gonna mate with a naga?" Osamu asks."I-" he looks up at Sakusa, then down at Suna, who has his eyes open now, staring at him with a pleading look. "I am."

The small broken sound that leaves Suna's still paralyzed body is heart-wrenching. Atsumu caresses Suna's face and whips away the tears streaming down his cheeks."I'm sorry, Rin." He kisses him on the forehead. "You'll find someone perfect. Someone who's deservin' and thinks yer the best man to walk the material plane. Ya deserve that, and I'm sorry that it's not me." 

Atsumu lays his tails over them both and presses their foreheads together to whisper, "I do love ya, Rin, just not like I needta."

He feels shaky arms wrap around him as Suna fights the venom. Atsumu's own tears fall into small splatters on Suna's skin. Really, it should have been Suna. It was  _ meant _ to be Suna, but something pulls him towards Sakusa, and he's powerless to fight it. He's not even sure he wants to fight it. Atsumu pulls back gently, easily breaking Suna's hold. 

Looking to Osamu, his brother embraces him tightly. "Are ya sure, 'Tsumu?"

"I am."

Osamu searches his face one more time, then smiles. "I hope you'll be happy then."

  
  


Watching his brother leave with Suna slung on his shoulder is something he won't soon forget. It's almost a surreal experience as a prelude to what is going to happen.

Turning to Sakusa, who has been patiently waiting, he says, "I'm all yers now, Omi-dono."

Reaching for Atsumu and stroking his cheek, he says, "Finally."

  
  


The moon cycles are important to several semi-divine beings and yokai alike. It's how they keep track of time. The moon can also bring out unique behaviors in these creatures. This year, a full supermoon happens to fall on the lunar solstice. Perhaps the moon is partially to blame for Atsumu's forgetfulness of this. 

This solstice, for humans, marks the longest night of the year. However, for kitsunes, it means the beginning of mating season. It's when individuals try to court and win over the affections of their prospective mate. And the full moon is said to increase the chances of reciprocation due to increased pheromone and arousal levels from the moon's influence. A supermoon only amplifies this. No wonder Suna came after him.

Atsumu isn't sure how the moon affects nagas, but Sakusa's scent rises as the night draws around them like a curtain. The large moon shines through, illuminating Sakusa's silhouette, and Atsumu feels it. 

When Sakusa kisses him, Atsumu stops breathing. Sakusa shudders and a sound - half growl, half moan - rumbles from the back of his throat. Shivers of pleasure shoot through him as Sakusa parts his lips, deepening the kiss. Atsumu presses against him, digging his fingers into soft, curly hair. Though nothing else about him feels that way. Atsumu sparks alive, his heart swelling to the point of near bursting. The rush of sensations crawling across his body is maddening. 

Sakusa's hands grab his hips, and he lifts Atsumu up as if he is made of air. His legs wrap around Sakusa's waist, and he knows Sakusa is moving, but Atsumu doesn't spare a thought as to where they're going. Their lips remain sealed. His tails twitch and graze across their bodies, seemingly having a mind of their own.

Atsumu is somewhat aware they have arrived at their destination when the world around them becomes even darker, and he's laid down on soft material. The swell of pheromones coats the air, and Atsumu feels himself getting warmer. He's panting and moaning as they devour one another, drowning in each other. Atsumu knows he's going into heat, but he's never been bubbling with anticipation for it before.

Sakusa’s hands move down, untying Atsumu's yukata and pushing it off his heated body. Sakusa's fingers skim over his skin, sending a rush of blood to every part of Atsumu's body. His own hands reach out, feeling the hard lines, dips, and ripples of his stomach. Now they're skin against skin. Their hips mold together and move against one another from where Sakusa is slotted between his legs.

"Omi." 

His arms tighten around Atsumu, crushing him against his chest. "So beautiful. I'll take care of you."

Through his heat haze, Atsumu sees two large cocks emerging from the area where Sakusa's human torso meshes with his serpentine body. Each alone is about the side of his forearm, and just as thick too. Atsumu moans at the sight, not even concerned about how this is going to work, though he probably should. Right now, he only wants Sakusa Kiyoomi. His alpha.

Kiyoomi laps at the scent glands on his neck, nipping and sucking on them. Atsumu's chest heaves with effort as his heat consumes his thought process, asking for more. His lips trail down Atsumu's body, paying attention to every curve along the way, worshipping his skin. Kiyoomi bites on his inner thighs, drawing a gasp from Atsumu's lips. Licking the tender area, he places Atsumu's legs on each of his shoulders. 

Then with no struggle, he holds Atsumu's hips up so only his upper back and shoulders touch the nest. Kiyoomi licks the slick dripping from his hole and plunges his tongue inside. Atsumu's eyes widen as he gasps, feeling the wet muscle so far inside of him. Rolling his tongue, Kiyoomi eats him out with hunger. Atsumu writhes in his firm grip but is powerless to actually move.

"Omi! Oh god, please!" 

He presses his face farther into Atsumu's ass, sucking at the sensitive skin. Atsumu's eyes roll back as he arches in the pleasure consuming him. The snake-like tongue inside him presses relentlessly against his prostate eliciting desperate cries and moans.

"Alpha! Please fuck me. Need yer cock."

Kiyoomi pulls back and gazes down at Atsumu's flushed body with his dark eyes."You want me to breed you?" he asks. "Make you my mate?"

"Yes, yes!"

Kiyoomi holds Atsumu completely in his arms and slowly maneuvers him to sink his large cock into his fluttering hole. It's huge. The stretch seemingly more than his body can take, but Atsumu wants it, wants his alpha inside of him.

"Oh, fuck!"

Kiyoomi kisses him again, trying to distract from the pain, and plays with his nipples. Sucking, pulling, rubbing against his sensitive buds and glands, Atsumu doesn't notice that there's no longer pain - the pleasure too overwhelming. Then he begins to move. 

Kiyoomi holds onto Atsumu's waist, wrapping his giant hands completely around him, and pulls him back onto his cock as he thrusts forward. Atsumu's back arches in a perfect C-shape, screaming Kiyoomi's name. The pace is brutal, and Atsumu scrambles for something to hold onto. He's floating - literally- in the air. He can only desperately cling to Kiyoomi's wrists as he's used like a cocksleeve.

"You're taking me so well, Atsumu. Such a good omega."

He mewls at the praise, his tails twitching sporadically behind him. Atsumu can feel it building inside of him, the hot tingly sensation of his orgasm. It rips through him like a sudden wave. He spurts over his abdomen completely untouched, and Kiyoomi works him through it, whispering praises.

"Do you want my cum, Atsumu?"

"Yes! Fill me up, want you inside."

Kiyoomi thrusts a few more times before he's coating Atsumu's inner walls white. He whines when his alpha lays him down and pulls out of him. "Don't worry, love," he says and kisses him. "I'm not done with you yet."

Then Kiyoomi's second cock is pushing into him. Atsumu grips at the soft material under him as Kiyoomi starts a slow pace. Atsumu can feel every vein dragging on his walls. Atsumu's body trembles from stimulation, but he hasn't had enough. He wants more, needs more. Kiyoomi's hands map his body, exploring, mouth sucking bruises along Atsumu's neck.

"Mm, you're going to carry my clutch, Atsumu. Be my mate and the mother of our children. Do you like that?"

"Yes, Omi." Atsumu clings to Kiyoomi's shoulders, trying to press closer. "I wanna be yers. Only yers."

"That's right. You're mine."

Kiyoomi pulls out, swiftly flips Atsumu over, and pushes back inside. Holding Atsumu's back to his chest, Kiyoomi licks at the gland he's going to bite into. He fucks up into Atsumu, shoving his cock in deeper, punching moan after moan out of Atsumu. Chants of  _ OmiOmiOmi _ ringing in the den.

Atsumu feels Kiyoomi shoot more cum into him right when a piercing pain sinks into the nape of his neck. Atsumu comes immediately, his vision whiting out at the sensation. When he comes to, Kiyoomi is coiled around him, licking the wound.

"Omi?"

"Hm?"

"I-'' Atsumu trembles with need, his heat still full-blown. "I need ya."

Kiyoomi mouths at his neck and places him on his cock that had plenty of time for a refractory period. "Don't worry, my little mate. I'll take care of you."

And take care of him he does. Kiyoomi moves Atsumu up and down his cock, impaling him over and over. He's figured out that nagas don't have knots, but who needs a knot when he's getting dicked repeatedly? 

Drool trickles out of Atsumu's mouth, running down his chin as he leans back against Kiyoomi's broad chest and moans, fucked out.

"You look so perfect Atsumu, bouncing on my cock like that."

Atsumu's chest bubbles with affection, a warm flutter. "Omi, so good."

When Atsumu comes again, he feels like there's something missing. He enjoyed the pain of his alpha marking him.

"Omi, bite me. Mark me all over."

Kiyoomi releases him, but his hands are soon replaced with his tail wrapping around Atsumu's waist, lifting him off the nest. Turning Atsumu to face him, he cups his face, kissing him as he's lowered back on Kiyoomi's waiting cock. 

Then he snaps. Kiyoomi grabs Atsumu's hair, yanking his head back, and sinks his teeth into his scent gland as he continues to piston into Atsumu's wet, cum filled hole. Atsumu screams in pleasure, babbling to Kiyoomi. Fangs release his neck, then Kiyoomi is on him again, marking the other side faster than his heat muddled brain can comprehend. 

Atsumu comes again and is fucked through it and beyond it. Kiyoomi doesn't let up, pounding into him with wild abandon and coiling around him tighter. He strikes Atsumu's peck next, his tongue swirling around Atsumu's nipple. At this rate, he isn't sure how many times he's come or Kiyoomi for that matter, he's filled to the brim with his alpha's cock and cum. He couldn't be more content.

  
  
  


Atsumu's heat lasts for five days. Kiyoomi ends up going into a rut as well, which extends their coupling for another two days. By the end of it, Atsumu has no voice, no more cum to give, and isn't sure he can move. 

Somehow, Kiyoomi seems more alive than ever and manages to unload an ungodly amount of cum into him each and every time. Atsumu is more exhausted than he's ever been in his entire life, but he's sated. He may not be able to feel his legs, but damn it, if it wasn't worth it. However, now that it's over he wonders if he's actually pregnant. Are kitsune naga hybrids possible?

Kiyoomi brings him food and water, laying down next to him."How are you feeling?" Atsumu gives a thumbs up. "Are you up for a bath yet? You're kind of disgusting."

Atsumu frowns with a thumbs down, gaining a disapproving look and a chuckle. Yes, he feels gross, but he doesn't want to move just yet. 

After Atsumu finishes his meal, Kiyoomi scoops him up and takes him down to the lake to bathe, disregarding the grunts of protest. However, Atsumu is too weak to put up a fight. And well, he does feel better being clean. Kiyoomi holds Atsumu in his arms back in his-  _ their _ den. 

Atsumu can't help but think about what may or may not be growing inside of him. Kitsunes gestate for a little under two months and give birth in their fox form. All kitsunes are in fox form for their first century of life. He has no idea about nagas and how that may affect things. Are their species even compatible? But the bond took, Atsumu can feel it thrumming with Kiyoomi's energy.

"Omi," he croaks.

"What is it, love? You should be resting your voice." He huffs and points to his stomach then shrugs. Kiyoomi hums in understanding. "I'm not sure. With nagas, some choose to lay their eggs after a couple of months and let them hatch, while others prefer to incubate them internally and give live birth. I don't think your body is even capable of making the eggshells."

Atsumu frowns, thinking about the outcome. Maybe it's not possible. Here he is moping about possibly not being able to have kids with his mate and just a week ago, he was dead set on not having a family for a long, long while. Oh, how things change. 

"Try not to worry about it," Kiyoomi says, rubbing his back. "We'll find out soon enough." 

Atsumu sighs. He's right.

  
  
  


A few weeks later, Atsumu knows without a doubt that he's pregnant. He can  _ feel _ it. And if he's not delusional, his stomach definitely has a bump.

"Omi, Omi, Omi!" he says, crawling on the back of Kiyoomi's tail. 

He quirks an eyebrow. "Yes?"

"Omi, I'm pregnant!"

Kiyoomi's eyes sparkle, and he turns to place his hand on Atsumu's stomach. "Are you sure?" He nods. 

The smile Kiyoomi has on his face makes Atsumu's chest swell. He picks Atsumu up and embraces him gently. Atsumu couldn't be happier. Now it's just a guessing game of how this is going to work.

  
  


They keep track of Atsumu's progress with the growth of his stomach and give their best estimate. Maybe three months to full term? But then what's going to come out of him? And how many? Kitsunes typically only birth one or two kits. Nagas, on the other hand, can go up to double digits. Atsumu is slightly terrified at the thought of popping out ten or more children.

Together they hypothesize what the babies might look like. Will they be hybrids? One or the other? It's truly an unknown. There's no record of a naga and kitsune mating before. At least that they are aware of.

Atsumu expresses interest in seeing Naga-loka, but Kiyoomi remains adamant that Atsumu stays close to their den while he's pregnant. So at his mate's request, he's mainly staying in. Winter is really starting to set in anyway. He and Kiyoomi spend several days cuddling together, keeping each other warm in more ways than one.

Between intimate moments of Atsumu sitting on Kiyoomi's cock while they just talk and truly get to know each other and heated moments where Atsumu writhes on their nest, he falls in love.

It's not even a groundbreaking moment, really, as he and Kiyoomi are already mates. However, the feeling shoots through him just like his orgasm while Kiyoomi is buried deep inside of him.

"I love ya, Omi!" he says with his head thrown back, arching off the nest.

Kiyoomi peppers his face with kisses before whispering, "I love you too, Atsumu."

  
  
  


By the third month, Atsumu is huge. He feels like he should just roll everywhere instead of enduring walking. His back hurts like a bitch, his feet a swollen, and he's fucking starving all the time. Fetuses are leeches. Fucking vampires sucking the life out of him.

"Omi~" he whines.

"What is it, baby?"

"I wanna cuddle, but I also don't want ya to touch me!" Atsumu huffs in frustration. Kiyoomi only chuckles and lays down next to him, avoiding skin contact to try and appease him. "I can feel 'em moving in there." He rests a hand on his distended tummy. "Feels weird."

"I can't wait to meet them."

"Yeah, me too."

Atsumu eventually scoots himself over to snuggle against Kiyoomi's chest. Pregnancy is weird.

  
  


That night, Atsumu wakes up to a wet sensation and wonders if he just peed himself. However, when his abdomen cramps he knows it was his water breaking.

"Omi!" he shakes his mate awake. "I'm in labor! What do I do?!"

Kiyoomi is immediately wide awake, and as Atsumu groans in pain, he also is at a loss. The only thing they really  _ can _ do is just wait for the babies to start crowning. And when the first one does, it's extremely painful.

  
  


Atsumu screams while Kiyoomi tries to both calm him and deliver the baby."It's alright, love, you're doing so well. Just one more push."

When the first baby is out, it's immediately apparent why it felt like Atsumu was pushing out a fucking watermelon. It has a hood just like a cobra flaring from its neck to the top of its head. 

"We have a son, Atsumu," Kiyoomi says, removing the thin sac the baby is encased in. Atsumu hears small whimpers from the child and takes in the rest of his appearance. 

He has a single scaly tail instead of a fluffy fox one and scaled legs. He holds the child as Kiyoomi begins to deliver the second. Out comes another boy that looks almost identical except for some markings. Atsumu almost cries in panic when Kiyoomi says there's another. This one, however, comes out much easier. It's a girl with fluffy fox ears and a naga body, though a single line of fur extends down the spine of the serpentine portion. Thankfully she's the last. 

Atsumu lays exhausted with his new family. Life is sure to get even more interesting. Who knows what to expect from these hybrid children? 

Kiyoomi lays close to him with the triplets across their chests and coils his tail around his family. This is his world right here, and he vows that nothing will ever harm them - not as long as he's here.

  
  
  


Atsumu and Kiyoomi watch as their three children play along the shoreline of Lake Itachi. They're growing fast, which isn't unusual for these kinds of beings. But Atsumu also wonders if it has anything to do with how large Kiyoomi is. Will they reach his size?

Kiyoomi curls an arm around his waist. "You look contemplative."

"I was just thinkin' 'bout when they grow up," Atsumu says, leaning into Kiyoomi's side.

"We still have a long while, but we could-"

Their daughter Nami slithers over waving her arms. "Papa! Dad! Is it okay if we go down to the beach?" 

Atsumu is about to protest when Kiyoomi agrees easily. Atsumu raises an eyebrow at him as their three kids scamper off.

"Well, someone's feelin' mighty passive today," Atsumu says, teasing his mate.

Kiyoomi's tail begins coiling around Atsumu. "Perhaps this turn of action suits my plans for the evening better."

Atsumu smiles suggestively to him, eyes glimmering with playfulness. "Oh? And just what might that entail?"

Pulling Atsumu closer, he splays his hands over his chest and slides them down to settle around his waist. "As I was saying earlier, we still have a long while, but we can always make more."

"Ya know kitsune mating season is only once a year."

"And I'm determined to prove you wrong.".

  
  
  


Kiyoomi has Atsumu spread out on his coiled up tail, already debauched, and they haven't even started yet. Not really at least. Kiyoomi pistons two fingers inside of Atsumu's hole, while his other had fucks his mouth with the same amount. Atsumu takes it all beautifully, sucking on his fingers, moaning when Kiyoomi hits his prostate just right.

"You look so perfect, baby," Kiyoomi says.

Atsumu moans, his tails spasming when Kiyoomi rubs at the base. Atsumu's hands try to cling to the scales on Kiyoomi's tail to ground himself. However, there's nothing there to grasp. His thrown back head is supported by Kiyoomi's thick coils. Drool runs out of the corners of his mouth as he tries to say Kiyoomi's name.

"You want my cock, baby?" Atsumu nods and whines, pleading.

Fingers are removed from both ends, and hands settle on his hips. He teases the head of one cock at Atsumu's entrance.

"Omi, c'mon, stop teasin'." 

Firmly holding Atsumu's hips in place, Kiyoomi presses inside in one long motion. Atsumu's hips twitch in his grasp, groaning at being filled. With the way Atsumu is laid on Kiyoomi's tail, it's the perfect angle to fuck up into him.

He starts slow, drawing almost all the way out before leisurely pushing back in, and it drives Atsumu mad. The feeling of Kiyoomi's cockhead pressing in and out of his tight hole provides a delicious sensation before it presses against his prostate, sending Atsumu into bliss.

"Fast- ah- faster, Omi."

Adjusting his hold on Atsumu's body, Kiyoomi drives his cock into him faster with each thrust. Atsumu wraps his arms and legs around Kiyoomi, as he's pinned against the coils underneath him. Kiyoomi presses his face into Atsumu's neck, licking at his scent glands. Atsumu tilts his head, just asking to be marked, and Kiyoomi takes the invitation, fangs piercing the soft skin. Atsumu howls, his vision going dark for a moment as he spills between their stomachs. Kiyoomi laps at the wound, working Atsumu through his orgasm.

"Do you want me to breed you again, my omega?"

"Yes, god, Omi, give me more of yer babies."

He groans, and thrusts into Atsumu, chasing his release. Kiyoomi comes, biting into Atsumu's other gland. Then he exchanges his cock for the other to continue fucking Atsumu. Slipping in with ease, he pounds into the wet heat. Tears stream down Atsumu's cheeks, barely noticeable against his flushed face. His body burns with pleasure, overstimulation shooting through his body.

"Kiyoomi!"

He kisses Atsumu, licking into his mouth, tangling their tongues together in a passionate tryst. It's wet, messy even, but they meet each other with all the desperation of a lover afraid to let the other go. They come together, wrapped up in the other. Their kisses turn soft and languid as they bask in the afterglow of their coupling.

Kiyoomi pulls back to look at Atsumu but keeps his cock held inside. Caressing Atsumu's cheek, he asks, "You think I put another baby in you, Atsu?"

Atsumu catches his hand, pressing it against him. "It wouldn't surprise me if ya somehow defied the laws of nature."

Kiyoomi chuckles and kisses the back of his hand. "I suppose we'll find out."

Atsumu sighs in contentment. "Yeah. We will."

"And if it doesn't happen this time, I'll gladly keep trying until I succeed."

Atsumu snorts but smiles at him. "We have an entire immortal life to make lots of babies."

"That we do. So let's start again now." Kiyoomi smiles mischievously, giving a small thrust.

Atsumu can't wait to see his beautiful family grow.

**Author's Note:**

> @TwilaWrites on Twitter


End file.
